Xilinx 8.2i Other Methods of Data Entry, Limit, Ls List Supported Devices, Rename Power Report

Models: 8.2i

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Chapter 10: XPower

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Other Methods of Data Entry

All asynchronous signals are set using an absolute frequency in MHz. All synchronous signals are set using activity rates.

An activity rate is a percentage between 0 and 100. It refers to how often the output of a registered element changes with respect to the active edges of the clock. For example, a 100MHz clock going to a flip flop with a 100% activity rate has an output frequency of 50MHz.

When using other methods of design entry, you must set the following:

Voltage (if different from the recommended databook values)

Ambient temperature (default = 25 degrees C)

Output loading (capacitance and current due to resistive elements)

Frequency of all input signals

Activity rates for all synchronous signals

If you do not set activity rates, XPower assumes 0% for all synchronous nets. The frequency of input signals is assumed to be 0MHz. The default ambient temperature is 25 degrees C. The default voltage is the recommended operating voltage for the device.

Note: The accuracy of the power and thermal estimates is compromised if you do not set all of the above mentioned signals. At a minimum, you should set high power consuming nets, such as clock nets, clock enables, and other fast or heavily loaded signals and output nets.

Command Line Options

This section describes the XPower command line options. For a list of available options from the command line, run xpwr -h.

-l (Limit)

-l [limit]

Imposes a line limit on the verbose report. An integer value must be specified as an argument. The integer represents the output number of lines in the report file.

-ls (List Supported Devices)

-ls [architecture]

Lists the supported Xilinx devices in the current software installation. Use the architecture argument to specify a specific architecture, for example Virtex.

-o (Rename Power Report)

-oreportName.pwr

Specifies the name of the output power report file. If a filename is not specified, the output power report is the input design filename with a .pwr extension.

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Xilinx 8.2i manual Other Methods of Data Entry, Limit, Ls List Supported Devices, Rename Power Report